Submarine mine and method of anchoring the same



April 21, 1931. cu uR I 1,802,239

SUBMARINE MINE AND METHOD OF ANCHORING THE SAME Filed Oct. 16, 1929 posed to enormous Patented Apr. 21, 1931 MARCO CUTURI, 0E BRU$SELS, BELGIUM PATENT OFFICE SUBMARINE MINE AND METHOD OF ANCHORING THESAME 3 Application filed October 16, 1529, Serial No. 400,038, and in France October 24, 1928.

The present invention relates to automatic submarine blockade mines. As is well known, these mines comprise substantially an impermeable float containing the explosive charge,

5 which 'float'is held at the desired depth by means of a cable or buoy rope which connects it to an anchor or grappler.

The problem which has to be solved in the anchoring of such mines, is the automatic locking of the float at the desired depth,

whatever be the depth of the sea.

The simplest and the most reliable method is that which consists in throwing the float and the anchor into the sea, and in allowing them to reach the bottom, in releasing thereupon the float which unwinds its cable and is stopped at the desired depth.

The regulation of the submersion of the float is done by means of an apparatus known 39 as a hydrostatic piston which will be hereinafter described. 7

This method'cannot however be used for great depths as the float would then be expressures.

sures would necessitate the use of walls of great thickness which, by considerably increasing the weight of the float, would oblige the designer to give it dimensions which would greatly complicate the operations of handling. -Moreover, beginning at certain pressures, whatever be the dimensions of the apparatus, its weight would become such that it would be impossible to cause it to rise to the surface.

To remedy this disadvantage, it has been proposed to place a fluid in the interior of the float at a pressure near the pressure of the medium in which is the mine. 7

This result has been obtained by pouring a liquefied fluid into the float or into a receiver arranged inside same, and then causing this fluid to evaporate and in consequence increasing the tension of its vapour by a source of heat controlled by the position of a valve which can be moved by a diflerence of pressure'between the outside and the inside of the float. V This means has the disadvantage of necessitating the use of a continuous source of heat to evaporate the liquefied gas and to heat the submerged valve, so as to prevent it sticking by the water freezing on contact with the vapour of the gas when same escapes.

In addition, a suitable source of heat may not be available at the moment of immersion.

Finally, the weight ofthe source of heat,for

instance of the'accumulators, increases the weight of the float. V 7

To remedy this disadvantage, the present invention provides for admitting into the inner case of the float the fluid into which it is immersed. V

The method of laying, according to the invention, consists in throwing to'the bottom of the sea, whatever be the depth, the float 6 and the anchor, the sea water being admitted into the interior of the float. When the whole reaches the bottom, the buoyancy of the float is ensured by replacing the water'contained in the same, by a fluid of a smaller density.

The float is thereupon released and on reachmg the desired depth, is stopped by any desired well known method. These pres- An embodiment of a submarine mine ac cording to the invention will be hereinafter described with reference to the accompanying drawing.

This drawing shows this mine diagramvmatically in section.

The submarine mine comprises substant1ally afloat 2 and an inner case 2?) containing between them the explosive charge 2a,

and intended to ensure its buoyancy. Before, being submerged, the float rests on its anchor 3 which usually comprises rollers 3a intended-to facilitate the movement of the mine.

In the construction shown in the drawing,

"the cable or'buoy rope 4 is wound on a drum or reel- 37) secured to the anchor 8.

In the construction accordi'ngto the invention, the inner case 26 of the float is in open communication with the outside through an opening 20, so that when the float is thrown overboard, the said case 2b is filled with fluid which will always have the outside pressure.

When the unit constituted by the float and the anchor, reachesthe bottom, the float must be given a suflicient buoyancy to ensure its rising and at the same time unwinding its instance, utilized, which takes buoy rope. According to the invention, this is ensured by replacing in the case 26 the water contained in the same, by a fluid of a smaller density, for instance by a gas contained in one or more tanks such as 5 connected to the case 2?) by pipes 5a. These pipes 5a are controlled by a time device such as 56, which opens them only after the expiration of a given time and in such a manner that the substitution of the fluids takes place only when the float has reached the bottom of the sea. These timedevices are well known to naval engineers, and those constituted by a piece of ammonia salt, which dissolve in water only after a given time, will be mentioned as an example.

In the construction shown inthe drawing, the cable 4 is secured with one of its ends to the anchor and passes over a pulley 2d secured tothe float, before being brought to the drum.

In order to render impossible a release of the float from the anchor before the substitution of the fluid has taken place completely, the drum is locked by a time device 3d of some known type.

hen the substitution of the fluids has taken place, and the drum has been released, the float will rise towards the surface and unwind its cable. A known brake device keeps the speed of rising of the float within normal limits. For stopping the float at the desired depth, the pulley 2d over which the cable passes in the float, is controlled by a hydrostatic device which controls a locking device which is adapted to lock the cable at a given moment. These hydrostatic devices are also known. They comprise substantial- 1y a piston exposed on one face to the pressure of a gas or to that of a spring and on the other face to the pressure of the fluid into which the float is submerged. As a rule a locking device is provided which prevents the hydrostatic device from acting during the sinking of the float. The hydrostatic de vice is released during the rising of the float.

During the rising of the float, thepressure gradually decreases, and the gas contained in the case 2?), expands,- and a portion of the same escapes through the opening 20.

In order to prevent the float from sinking under the action of its turning about a horizontal axis, produced by the eddies or by a dredging operation, and producing the ad- 5 mission of sea water into the case 26, according to the invention, the orifice 2c is closed when the float stops at the desired depth.

In order to bring about the closing in question, the sudden tension of the cable is, for place at the moment of stopping of the float.

The pulley 252 over which passes the cable, may be secured to a valve 2; held in the upper part of the float by means of fragile parts, such as pins, of phosphor bronze. These parts would break under the action of the shock caused .by the stoppage of the float, owing to which the valve 2; would be allowed to descend into the opening 20.

Moreover, according to the invention, provision is made for ensuring a tight closing of the opening 20 by exposing the valve 2f to a pressure acting from the interior of the float. To that end, a tank 29 containing fluid under pressure, is automatically opened when the valve 2f is brought in place in the opening 20. In order to attain this, the valve opening the said tank could be controlled for instance by the movement of the valve 2/. Thus when the container 29 is lowered with the valve 2 relatively to the float, the opening valve PM of the container 29 (which washeld closed by a locking device) may be freed by means of a cable 2j secured to the locking device and to the wall of the chamber 2?). The length of this cable is such that it exerts a pull on the locking device before the valve 2; closes the aperture 20.

What I claim is:

1. A submarine mine of the type comprising an anchor and a hollow float to be sunk to the bottom of the sea, whereupon the float is released from its anchor and automatically rises and is anchored at a predetermined distance below the surface of the water, the interior of which float is in communication with the exterior during the dropping to the bottom, means for substituting for the water of the sea a fluid of lower density, a member for closing the communication between the interior and the exterior of the float after the latter has been stopped near the surface of the water.

2. A submarine mine of the type comprising an anchor and a hollow float to be sunk to the bottom of the sea, the interior of which float is in communication with the exterior during the dropping to the bottom, means for substituting for the water of the sea a fluid of lower density, a member for closing communication between the interior and the exterior of the float, fragile parts for maintaining the said closing member in open position, a cable, and a connection between said closing member and the cable so that the latter breaks the said fragile parts when it stops the float near the surface of the water.

3. A submarine mine of the type comprising an anchor and a hollow float to be sunk to the bottom of the sea, the interior of which float is in communication with the exterior during the dropping to the bottom, means for substituting for the water of the sea a fluid of lower density, a member for closing the communication between the interior and the exterior of the float after the latter has been stopped near the surface of the water, and means for maintaining the said closing valve in the closing position after it has reached the latter.

4. A submarine mine of the type comprising an anchor and a hollow float to be sunk to the bottom of the sea, whereupon the float is released from its anchor and automatically rises and is anchored at a predetermined distance below the surface of the water, the interior of which float is in communication with the exterior during the dropping to the bot-v tom, means for substituting for the water of the sea a fluid of lower density, a member for closing the communication between the inte rior and the exterior of the float after the latter has been stopped near the surface of the water, a tank in the interior of the float containing a fluid under pressure, and a control device for the opening of said tank, so that %aid opening is effected at the closing of the oat.

5. A method of laying submarine mines consisting in dropping a float and its anchor to the bottom of the sea, putting the interior of the float in communication with the sea during the descent of the mine, substituting for the water contained in the interior of the float a fluid of lower density after the mine has reached the bottom of the sea, thereupon releasing the float from the anchor, and stopping the latter near the surface of the water.

6. A submarine mine of the type comprising an anchor and a float to be sunk to the bottom of the sea, whereupon the float is released from its anchor and automatically rises and is anchored at a predetermined distance below the surface of the water, comprising a hollow float the interior of which is in communication with the exterior during the'dropping to the bottom, to allow sea water to enter into said float, tanks containing a fluid under pressure of lower density than sea water, means for transferring said fluid under pressure from the tanks into the interior of the float, and means for transmitting to the inner face of the outer casing of the float the pressure existing in the interior of said float.

7 A submarine mine of the type comprising an anchor and a hollow float to be sunk to the bottom of thesea, whereupon the float is released from its anchor and automatically rises to a predetermined distance below the surface of the water, comprising tanks mounted on said anchor and containing a fluid under pressure of lower density than sea water, and means for transferring said fluid under pressure from the tanks into the interior of the float.

8. A submarine mine of the type comprising an anchor and a float to be sunk to the bottom of the sea, whereupon the float is released from its anchor and automatically rises and is anchored at a predetermined distance below the surface of the water, comprising a hollow float the interior of which is in communication with the exterior during the dropping to the bottom, means for transmitting to the inner face of the outer casing of the float the pressure existing in the interior of said float, tanks mounted on said anchor and containing a fluid under pressure of lower density than-sea water, means for transferring said fluid under pressure from the tanks into the interior of the float, and a time device for controlling the beginning of said transfer.

9. A submarine mine of the type adapted to be maintained at a desired depth by a cable connected with an anchor at the bottom of the sea comprising a float, the interior of which is in communication with the exterior duringthe dropping to the bottom, tanks mounted on said anchor and containing a fluid of lower density than sea water, means for transferring said fluid under pressure from the tanks into the interior of the float, and a time device for releasing the float from its anchor after said transfer.

In testimony whereof I aflix my signature.

MARCO CUTURI. 

